A light emitting element like a laser diode or more particularly a VCSEL (vertical cavity surface emitting laser) is conventionally provided with a driver circuit which supplies power to the light emitting element, wherein it is aimed for the supplied power being basically constant and at least in the vicinity of a power value allowing for maximum efficiency. Such conventional driver circuit may for example include a power factor correcting first converter stage (PFC) connected to one or more capacitors, which store energy so that a second stage can deliver a basically constant power to the light emitting element. Such design is costly due to the constraints on characteristics, performance and accuracy of the used components.